1. Field of the Invention
The present invention relates generally to data processing, and more particularly but not exclusively to scanning of data for malicious content.
2. Description of the Background Art
Content filtering systems are employed in computer systems to scan incoming data for malicious content, such as computer viruses, spam, unwanted content, and unauthorized network intrusion. A content filtering system typically includes a knowledge base against which an incoming data is compared. An example knowledge base is the pattern file of an antivirus program. A pattern file contains the patterns or signatures of known viruses. An antivirus program compares the contents of an incoming data against the contents of a pattern file to determine if the data has a virus. A pattern file is periodically updated to include the patterns of newly discovered viruses.
The size of a knowledge base increases as the knowledge base is updated to include more information. In the case of antivirus programs, pattern files get larger as more viruses are discovered. The increasing size of a knowledge base strains the resources (e.g., storage and processor) of the computer running the content filtering system. This problem is especially significant with computing devices that are not easily upgradeable.